The present invention generally relates to optical films, and more particularly relates to measuring of and cutting of optical films, and even more particularly relates to methods and apparatuses for precision measuring and cutting of optical films to provide for precise alignment of optical axes with edges of the film.
In the past, optical films have been used to enhance the performance of liquid crystal displays and other optical devices. Avionics engineers have routinely endeavored to enhance the optical performance of such liquid crystal displays. When multiple optical films are used in which each film has a predetermined optical characteristic, it is often desirable to attempt to align these films during the assembly process. A common approach has been to accept the manufacturer""s tolerances of orientation of the optical axes with respect to the edges of the films and then use these edges to align the optical axes.
While this approach has benefits of simplicity and ease of use, it also has significant drawbacks. A significant problem of this type of approach is that it may allow an excessive amount of angular tolerance to accumulate between films, especially with compensation modules having multiple films and the most rigorous performance specifications.
Consequently, there exists a need for improved methods and apparatuses for aligning optical films in a multi-film LCD.
It is an object of the present invention to provide high performance LCDs.
It is a feature of the present invention to utilize a sensor coupled to a cutting machine; the sensor is used for measuring optical characteristics of a film to be cut by the cutting machine.
It is an advantage of the present invention to achieve more precise angular alignment of the various optical axes of numerous films with respect to their edges cut by a cutting machine.
It is another feature to use an LED and sensor to measure optical characteristics of such films.
It is another advantage of the present invention to provide high angular resolution of the optical axes with respect to edges of an optical film which are cut by a cutting machine.
The present invention is an apparatus and method for measuring and cutting optical films which are designed to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features and achieve the already articulated advantages. Accordingly, the present invention is a method and apparatus which includes a sensor, disposed on a cutting machine, for measuring light transmitted through a film, and generating an optical axis alignment signal which is then used in the process of cutting optical films.